class Calculator:
    @staticmethod
    def add(a, b):
        return a + b

    @staticmethod
    def sub(a, b):
        return a - b

    @staticmethod
    def mul(a, b):
        return a * b

    @staticmethod
    def div(a, b):
        return a / b


if __name__ == '__main__':
    print(Calculator.add(6, 3))
    print(Calculator.sub(6, 3))
    print(Calculator.mul(6, 3))
    print(Calculator.div(6, 3))
